<html lang="en">
    <head>
        <meta charset="UTF-8">
        <meta http-equiv="X-UA-Compatible" content="IE=edge">
        <meta name="viewport" content="width=device-width, initi
        al-scale=1.0">
        <title> 特殊场景this绑定实验 </title>
        </head>
        <body>
        <button>按钮 </button>
        <script>
           setTimeout(function() {
 console.log("定时器函数:", this);
 }, 1000);
 var btnEl = document.querySelector("button");
  btnEl.onclick = function() {
  console.log("btn的点击（onclick）:", this);};
  btnEl.addEventListener("click", function() {
 console.log("btn的点击（addEventListfdener）:", this);});
 var names = ["abc", "cba", "nba"];
 names.forEach(function(item) {
 console.log("forEach:", this);
 }, "aaaa");

       </script>
        </body>
        </html>